Device for displaying moving images in the background of a stage

ABSTRACT

An article such as for example a motor vehicle at a publicity function is to be represented in front of different viewers (38) in the background of a stage (28) in the form of a virtual image (26). A presenter (40) is to stand in the image and give explanations. Disposed above the stage (28) is an image source (12, 14). It projects an image, a film, on to a reflecting surface (18) on the floor (30) of the stage (28). Behind that reflecting surface (18) a transparent smooth foil (20) extends at 45° from the ceiling (32) to the floor (30). The image produced by the image source (12, 14) appears to the viewers (38) as a virtual image (26) behind the foil (20). The presenter (40) stands behind the foil (20) and in the middle of the image.

The invention concerns an apparatus for representing moving images inthe background of a stage or the like using an image source.

Transparency lectures or presentations are known, and that expression isa well-established piece of terminology. In a transparency presentationthe presenter projects still images or pictures on to a projectionscreen. The presenter himself stands outside the light cone between theprojector and the projection screen and comments on the images. Insteadof the transparency projector the presenter can also use a filmapparatus. In that case moving images appear on the projection screenand the presenter comments thereon. In both cases the presenter standsoutside the light cone. He does not appear on or in the image himself.If he were to move into the light cone he would mask off a part of thelight beam. Instead of the image, the shadow of the presenter would thenappear on the projection screen. If the presenter wants to direct theattention of his viewers to a given point in the image he uses for thatpurpose a pointer or a light with a sharply focussed light beam.

The foregoing kind of presentation is sufficient for image and filmpresentations for photographic and film amateurs. Travellers who showfilms or transparencies of their travels to a wide circle of viewers canalso use that kind of presentation without detriment. The viewers areonly interested in the film or the transparencies and the words of thepresenter. They attribute only slight significance to the manner ofpresentation and the technical equipment involved.

The position is different if the viewers do not have any particularinterest in the articles to be shown and an interest first has to bearoused. The position is also different when the film presentation is totake place at a high technical level, for overriding reasons. Thesituation is also different if the film presentation is to be made morerelaxed and less monotonous and linked to so-called display effects.

A theatre production is described as a ghost trick in the literature(for example Buhnentechnische Rundschau, BTR 3/1990, pages 24 and 25),involving disposing a pane of glass inclinedly in the front region ofthe stage. An actor is positioned beneath the pane of glass and in alowered part of the stage. He is bedecked with wide white garments andrepresents the ghost. He is lit by a spotlight which is also disposedunder the stage. The image of that actor representing the ghost isprojected on to the pane of glass and appears to the viewers behind thepane of glass a virtual image. In that theatre presentation a secondactor is on the stage. He represents a hero or sorcerer who conjures upthe ghost.

On the basis thereof, the object of the present invention is anapparatus with which film and image presentations can be made relaxedand the presenter himself can move into the image without therebyinterfering with reproduction of the image on a projection screen orgenerally on a surface. In accordance with the invention, that object isattained in an apparatus of the kind set forth in the opening part ofthis specification, in that a reflecting surface is arranged on thefloor of the stage in the central region thereof, a transparent smoothfoil extends between the floor and the top or ceiling of the stage overthe entire width thereof in such a way that its lower end is held to aposition between the reflecting surface and the background and its upperend is held to the ceiling at a position which is disposed furtherforwardly, and the image source is arranged at the ceiling in front ofthe upper end of the foil which is held there, and is directed on to thereflecting surface.

The apparatus according to the invention makes use of the physicalprinciple that any motor car driver experiences on the windshield of hisvehicle. An article lying on the storage surface in front of thewindshield is reflected therein in such a way that it seems to the motorcar driver to be disposed in front of the windshield, as viewed in thedirection of travel. In the case of the apparatus according to theinvention the article to be represented is projected by the image sourceon to the reflecting surface which corresponds to the above-mentionedsupport surface, and it is then reflected in the transparent smooth foilin such a way that it appears to the viewer on the background of thestage. The foil which extends over the entire width of the stage andwhich is held to the floor and ceiling thereof acts like the windshieldin a motor vehicle. A viewer at any point in the auditorium believesthat he is seeing any article reflected by the reflecting surface on tothe foil, behind same. The presenter stands on the stage outside thelight cone of the image source. As viewed from the auditorium, he standsbehind the reflecting surface. That means that his image is not formedon the background, nor does he disturb the image representation thereon.He can draw the attention of the viewers to given details in the imagerepresentation, without making use of a pointer or a light. He canlikewise move with the images and interpret the reproduction thereof byvirtue of his body language.

Desirably the foil extends at an angle of about 45° relative to thefloor of the stage. The image source can be a display screen tube with avery high degree of resolution. It can be controlled by a computer. Thatmeans that the image can also be electronically influenced. Desirably acomputer-controlled intelligent light amplifier (also known as an ILA)is used as the image source. It is oriented horizontally and emits lightin the direction of the auditorium. Accordingly its longest extent liesin the horizontal and it can be easily concealed from the viewers. Sothat the light which it radiates reaches the reflecting surface, afurther embodiment provides that a mirror is arranged in front of thecomputer-controlled light amplifier and the latter is directed on to themirror and the mirror receives the light emitted by the light amplifier,is directed on to the reflecting surface and projects the light on tosame.

If possible the viewer should not notice how the image in the backgroundof the stage is produced. Therefore the light amplifier and the mirrorare desirably covered over forwardly by a curtain or a board whichextends over the entire width of the stage. The foil itself is under avery high tensile stress of up to 8t. In that way it is held tautlysmooth and the image is not distorted. The foil is preferably withoutany inclusions. It is also to be very smooth on its front side and itsrear side. It is also to be very thin. Finally the foil is to reflectbetween 30 and 50%, preferably 30%, of the light impinging on it. Such afoil is particularly well suited for the purposes according to theinvention. The absence of inclusions and the smooth front and rear sidesthereof result in very slight and imperceptible distortion effects. Thefact that the foil is very thin serves the same purpose. Reflectionphenomena at the front and rear sides thereof thus coincide. The foilused for the purposes according to the invention is generally subjectedto further processing as transparency or 35 mm films. When used as atransparency film, it is cut up into the format of the transparency or35 mm films. When it is used for the invention the foil has a surfacearea of at least 3 m times 4 m.

In a desirable embodiment the foil is rolled on to a winding tube. It issuspended therewith at the ceiling of the stage. Desirably it is fixedto the ceiling, together with the intelligent light amplifier. The freeend of the foil can be pulled off the winding tube and is fixed to thefloor of the stage. A support mounting arranged on the floor of thestage is used for that purpose.

The reflecting surface may be a white projection screen which is to belaid on to the floor of the stage. The reflecting surface however mayalso be a simple white coat of paint. As the presenter moves outside itand more specifically behind it, it retains its reflecting propertiesfor a very long period of time.

The apparatus according to the invention is advantageously used inconnection with a stage with a floor which can be raised and lowered.The reflecting surface, the projection screen, the coat of paint or thelike, is disposed on that part of the floor, which can be raised andlowered. When the floor is lowered the spacing between the image sourceand the reflecting surface is increased. As a result the virtual imagewhich appears in the background of the stage is displaced rearwardly.

The apparatus according to the invention is to be easy to transport fromone location to another and to set up at different locations. For thatpurpose, in a desirable embodiment, the invention provides that itscomponents are enclosed by a lattice frame and can be secured thereto.Desirably, the lattice frame has units which can be set up on the twosides of the apparatus or the stage thereof and which each have a lowergirder portion, an upper girder portion, a front girder portion and aback girder portion. The lattice frame units which can be set up on thetwo sides of the apparatus or stage can be connected together bytransversely extending struts.

Desirably the winding tube is secured to the upper girder portions byway of brackets while the mounting support which holds the free end ofthe foil is fixed to the lower girder portions.

The invention will now be further described by way of the example of theembodiments illustrated in the drawing in which:

FIG. 1 is a simplified diagrammatic side view of the apparatus accordingto the invention,

FIG. 2 is a more detailed diagrammatic side view of the apparatusaccording to the invention, simultaneously showing the auditorium,

FIG. 3 is a side view of the stage similarly to the illustration in FIG.2 with the floor lowered,

FIG. 4 is a view of the auditorium and the stage looking in thedirection of the line IV--IV in FIG. 2,

FIG. 5 is a side view of the apparatus according to the invention whenusing the lattice frames surrounding it, and

FIG. 6 is a view in the direction of the line VI--VI.

FIG. 1 shows the physical principle of the apparatus according to theinvention with the computer-controlled intelligent light amplifier 12which acts as an image source, the mirror 14 which in the view in FIG. 1is arranged to the left in front of it and which projects the lightradiated on to it from the light amplifier 12 on to the reflectingsurface 18 in the form of a light cone 16 as indicated by two brokenlines, the foil 20 with its lower holding means in the form of amounting bracket 22 and its upper holding means in the form of a windingtube 24 and the virtual image 26 which is represented in the backgroundof the stage. The computer-controlled intelligent light amplifier 12projects a moving image on to the mirror 14. This projects it on to thereflecting surface 18 which projects it on to the foil 20. From thepoint of view of a viewer who is at the left in FIG. 1--see FIG. 2--amoving image appears in the background as a virtual image 26.

FIGS. 2 and 3 show a practical application of the apparatus according tothe invention at a presentation or lecture function. More specificallyFIG. 2 again shows the stage 28, the floor 30 thereof and the ceiling 32thereof. Extending under the ceiling 32 of the stage 28 over the entirewidth thereof is a curtain or a cover rail or board 34. It covers overin a forward direction the computer-controlled intelligent lightamplifier 12 and the mirror 14. The viewers 38 sit in the auditorium 36.The presenter or lecturer 40 stands on the stage 28 behind thereflecting surface 18. The reflecting surface 18 is for example aprojection screen or a coat of white paint. The double-headed arrowshown under the floor 30 is intended to indicate that it can be raisedand lowered. FIG. 2 shows the floor 30 at its normal height. The virtualimage 26 appears in the background of the stage 28 at a given location.FIG. 3 shows the same stage 28 with the floor 30 lowered. When the floor30 is lowered the virtual image 26 moves rearwardly, towards the rightwhen looking at FIGS. 2 and 3.

FIG. 4 shows a practical application of the apparatus according to theinvention in a presentation function relating to motor vehicles. FIG. 4shows a presentation article 42, in this example being a motor vehicle.The viewers 38 see it in the background as a virtual image. They do notrecognise that this involves a reflection at the reflecting surface 18and the foil 20. They only see how the presenter 40 moves freely infront of the motor vehicle, points with his arms and hands to the motorvehicle and parts thereof, explains details in words, and in so doingneither interferes with nor in any way influences the reproduction ofthe motor vehicle in the background in the form of the virtual image 26.

FIGS. 5 and 6 show the transportable embodiment of the apparatusaccording to the invention, which can be set up at any desired location.Lattice frames 44 which can be set up at both sides of the apparatusserve for that purpose. Each lattice frame comprises a lower girderportion 46, an upper girder portion 48, a front girder portion 50 and aback girder portion 52. Lattice frames of that kind are known. Eachgirder portion comprises a plurality of parts which can be releasablyconnected together. For the purposes of erecting the apparatus, theparts of the girder portions are fitted together and joined together.For transportation purposes they are separated from each other and canbe transported in the form of comparatively small units on a truck orthe like. As shown in FIG. 5 the computer-controlled intelligent lightamplifier 12 and the winding tube 24 are fixed to a bracket. The bracketis in turn fixed to a transverse strut which connects the two uppergirder portions 48. The same applies in regard to the mirror 14. Whenthe apparatus is erected the foil 20 is pulled off the winding tube 24,fixed to the mounting bracket 22 and then tensioned. The reflectingsurface 18 is laid on the floor in the form of a plate or the like whichis coated or painted white, or in the form of a projection screen. Thestage 28 on which the presenter 40 stands when making his presentationis composed of parts which are known per se on their own and it iserected in the rearward region of the apparatus.

I claim:
 1. Apparatus for representing moving images in the backgroundof a stage using an image source, said stage including a floor, aceiling disposed vertically above said floor and a background disposedtherebetween, said apparatus characterised in that a reflecting surface(18) is arranged on said floor (30) of said stage (28) in the centralregion thereof, a transparent smooth foil (20) extends between saidfloor (30) and said ceiling (32) at a position which is disposed furtherforwardly, and the image source is arranged at the ceiling (32) in frontof the upper end of the foil (20) which is held there, and is directedon to the reflecting surface (18).
 2. Apparatus as set forth in claim 1characterised in that the foil (18) extends at an angle of about 45°relative to the floor (30) of the stage (28).
 3. Apparatus as set forthin claim 1 or claim 2 characterised in that the image source is acomputer-controlled intelligent light amplifier (12).
 4. Apparatus asset forth in claim 3 characterised in that a mirror (14) is arranged infront of the computer-controlled light amplifier (12) and said lightamplifier is directed on to the mirror (14) and the mirror (14) receivesthe light radiated from the light amplifier (12), is directed on to thereflecting surface (18) and projects the light on to said reflectingsurface.
 5. Apparatus as set forth in claim 4 characterised in that thelight amplifier (12) and the mirror (14) are covered over forwardly by acurtain extending over the entire width of the stage (28).
 6. Apparatusas set forth in claim 1 characterised in that the foil is subject to atensile stress.
 7. Apparatus as set forth in claim 6 characterised inthat the foil (20) has a surface area of at least 3 m times 4 m. 8.Apparatus as set forth in claim 7 characterised in that the foil (20) isrolled on a winding tube (24) and can be pulled off same and can befixed with its free end in a support mounting (22).
 9. Apparatus as setforth in claim 1 characterised in that the reflecting surface (18) is acoat of white paint.
 10. Apparatus as set forth in claim 1 characterisedin that the reflecting surface (18) is a white projection screen. 11.Apparatus as set forth in claim 1 characterised in that the floor (30)of the stage (28) can be raised and lowered.
 12. Apparatus as set forthin claim 4 characterised in that light amplifier (12), mirror (14),reflecting surface (18), foil (20) and stage (28) are enclosed by alattice frame (44) and can be fixed thereto.
 13. Apparatus as set forthin claim 12 characterised in that the lattice frame (44) includes twounits which can be set up on both sides of the stage (28) and each unithas a lower girder portion (46), an upper girder portion (48), a frontgirder portion (50) and a back girder portion (52).
 14. Apparatus as setforth in claim 13 characterised in that the two lattice frame unitswhich can be set up on both sides of the stage (28) can be connected bytransversely extending struts.
 15. Apparatus as set forth in claim 4characterised that the light amplifier (12) and the mirror (14) arecovered over forwardly by a cover bar (34) extending over the entirewidth of the stage (28).